https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69371
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to Ed Smith-Rowland from comment #2) > The message looks more like a header - cmath - is not included or that > the line > // { dg-options "-D__STDCPP_WANT_MATH_SPEC_FUNCS__" } > or equivalent is not set. > > But my fresh checkout has the necessary things.. Yes, I wondered if including <limits> first was somehow preventing the extra bits of <cmath> being included but it looks OK to me. Preprocessed source will tell us what's happening.